Microcapsules are small particles of solids, or droplets of liquids, or combinations thereof, inside a thin coating of a material such as gelatin, lipids, starch, cellulosic proteins such as whey proteins, polysaccharides, wax or polyacrylic acids.
The use of microencapsulated compounds has many advantages over the use of unencapsulated compounds. In particular, microencapsulation separates the core material from its environment and provides for taste-masking, controlled release rates, reduced toxicity, and protection against oxidation and moisture, as well as prevention of caking. The release rate of the core material and the diffusion of the core material through the capsule wall can be controlled by varying the wall composition, its thickness and the structure of the walls.
Simple or complex coacervation microencapsulation techniques can be used to make microcapsules. Although these techniques are known, the processes can be long, can involve undesirable solvents, can result in unwanted agglomeration, and can have limitations in controlling microcapsule size.